With the first Half-Life game in more than a decade set to come out in March, series creator Valve has made every game in the franchise free to play for the next two months. As long you have Steam installed on your Windows, Mac or Linux computer, you can play all of Gordon Freeman's adventures, including Half-Life and its excellent Opposing Force expansion, as well as Half-Life 2 and its two subsequent DLC episodes.
According to Valve, it's holding the promotion to help players get ready for Half-Life: Alyx. The upcoming VR title is set before the events of Half-Life 2 and will feature many of the characters that play a part in later titles. "The games share characters and story elements," the company said. "The Half-Life: Alyx team believes that the best way to enjoy the new game is to play through the old ones, especially Half-Life 2 and the episodes, so we want to make that as easy as possible."
If the now quaint graphics of the original Half-Life put you off, make sure to also check out Black Mesa. It's a fan-made recreation of the 1998 classic that adds new, more modern graphics, as well as tweaked gameplay elements, areas to explore and more.